"If you imagine [the area] from the eyebrows down to the upper jaw, the whole central part of the face had been shattered.

"It was like a jigsaw puzzle because we had to find the bone pieces - maybe 30 or so - and put them all back together."

The medical team then inserted a dozen titanium plates to hold the bones together, recreated an eye socket, screwed the upper jaw and locked the missing teeth into place.

But as horrific as the injuries were, they may have kept Fisher alive. "These facial fractures probably saved his life because they absorbed a lot of the impact."

Fisher was the latest victim in a worrying trend, he said. Until recently, most patients with such severe injuries would have been in vehicle crashes, but about five years ago "inter-personal violence" took over as the leading cause.

Fisher's were among the worst violence injuries he had come across in his career. "This is supposed to be a civilised society, so this should not happen."

Fisher's father, Brian, said his son's injuries were "very extensive".

"He took a very, very brutal beating . . . a very serious stomping."

The brain damage he suffered, which doctors likened to the equivalent of "two or three little strokes", was still of most concern.

"With any brain injury, there's very serious consequences. I don't think he's ever going to be himself again.

"The paralysis on the right side is very worrying, he's got no movement in his right arm and only some movement in his right leg."

His son had initially been kept in an induced coma by hospital staff for 3 days. He was now sleeping about 20 hours each day, but was able to talk "a little bit" while awake.

At his bedside was "the tight five" of partner Freida, brother Paul, sister Dee and parents Brian and Noeline.

The surgery came on the same day the alleged attacker had more charges laid against him in Masterton District Court.

Milton Haira, 25, made a brief appearance before being further remanded in custody without plea until next month.

A charge of assault on Fisher was withdrawn and replaced with a more serious charge of wounding with intent to cause grievous bodily harm.

Haira was also charged with assaulting four teenage girls at the party, all 14, and of threatening to kill three members of the group.

Police have said the gathering, mostly of girls, was supervised. Haira, who lived nearby, arrived intoxicated. When he refused to go, the mother of the girl who lived there asked Fisher to help eject him. An argument broke out, and Fisher was attacked.